New reference
speakers - "Delusion P24"
Finished in
MARCH 2009 - read on the bottom of the page.
P24 Anniversary
Edition
(18th anniversary
of my speakerbuilding)
WITHOUT DOUBT, Mr.
LAMPIZATOR STARTED RUNNING IN CIRCLES. CIRCLES
AROUND THE SAME CONCEPT of Open Baffle/SABA.
AFTER DISCOVERING
SABA GREENCONE DRIVERS, I HAVEN'T MADE ANY
PROGRESS.
They are that
good. Sabas I mean.
The only way out
of the ballpark hole is to go "expenceive exotica",
because there are no other areas for me to discover. I have tried
commercial standard drivers, vintage drivers, and I pretty much know
them all.
I generally
refused to use $$$ drivers, hand-made in Japan from
rice paper. As much as I refuse to start saving for Ongaku and the
like.
Let me admire those from a safe distance and walk firmly on earth.
Having said all
that I broke this rule and I treated myself to a very
special driver, hand made in Serbia by Mr. Aleksandar Radisavljevic, a
very nice man and talented ribbonbuilder.
I selected this
ribbon solely on the basis of good opinion on internet.
I made an
assumption, that if someone is from Serbia (I mean small
country not usually associated with High End or metalwork), he must be
damn good to make such success in this americanized world.
So the plan is
this: to make the most crazy marriage of 21st
century hi-tech ribbon to the vintage Altec Lansing from the 60's.
Russian tubes,
Ukrainian amps, German CD, American drivers and Serbian
ribbons. And a Polish maker. Enter The P24...
The Target:
uncompromised, full scale, full bandwidth speakers for
the tube amplifier
The Plan:
- three way
- 96 dB/m/W
minimum
- open baffle
- musical
- transparent
- uncolored
- fast transient
- time coherent
- biwired
- easy to drive
by OTL amps
The solution:
TWEETER
SUMMER 2007
Raal
http://www.raalribbon.com/products_flatfoil_140-15.htm
Mr. Aleksandar
Radisavljevic was totally deaf to my begging for special
discount. Despite my price pressure he basically told me to go and get
stuffed (in a very polite and friendly way). That caused my
curiosity to rise. How dare he to treat Doctor Lampizator, the self
proclaimed
Prometheus like this? !!!
Gee, these
drivers simply MUST be good. Or rather "they better be good".
I ordered the
speakers for the retail price and I mumbled something
like a promise of my
vengeance in the www review. Wait my man, I will mop the floor with
these
drivers if they are bad.
A week later,
upon close inspection when they arrived - my eye pupils
went wide open. Full F1,4 iris. What I was holding did not even
resemble the Ravens. This is some serious shit - I thought.
I could not
possibly wait to try them with the Altecs a month later or
so when the Biflex will arrive, so I immediately hooked them to my Saba
Greencone P12 setup in place of the Saba10 tweeters. See photo below.
I made a quick
XO consisting of a CLC filter third order - 4uF / 0,6 mH
/ 4uF (caps are PIO)
I sat down in my
chair and with shaking hands I pressed PLAY.
A biig smile,
and I was taken to heaven (a sinner or not - I went
straight there through VIP gates).
Oh Dear Lord do
they blend seamlessly! Total magic and match made in heaven. The
experimental XO without any fine tuning sounds like there is nothing
more to do. A month later i shorted the second cap, leaving only the
first series 4uF) The top end extension, the purity, the
tonality, the zzing
and the zzang, all is there !
Lack of any
distortion, any coloration, any sizzling,
spitting, sibilance - absolutely none of the above. I must admit I did
not expect them to be that good. Also the critical SPL is right there
with the Greencone around 98 dB.
The amount of
detail information available from my Lampizator CD
players is scary on the RAALs.
I do not know
how a standard op-amped CD with transistor amplifier
would
sound on these, because the electron microscope which the RAALs are
would mercilessly show the dirt in the op-amped system. These drivers
do not "make the system sound good", they make a good system sound
true. But on my
system this is the best I can imagine. They make music, they reveal
detail, they do the 3D, the goosebumps, etc. The whole package.
And by the way -
the foam waveguides do work ! I love it! Just what the
Raven was missing.
After a month
-after I slightly touched the XO, I just listen, listen
listen. I can not name a single fault about the sound or construction
of the RAAL, except that I completely don't understand the wire
terminals they used. (After a year I confirm everything) But that
is a minor issue compared to the fact
that one of the best tweeters ever made can be had for an acceptable
sum of around 1000 Euro a pair including shipping by DHL and all EU
duties and VAT. Cheap ??? Surely not. But value for money - YES.
The test drive
.......
Feb
29th 2008:
All of the above
blah blah was written about the RAALs working with
SABA mids, awaiting partnering with the Altecs as below.
I decided to
keep the RAAL XO and just adjust the Altec to the RAAL's
curve. I succeeded with the below XO for the Altec.
The blend is not
as seamless as with the Sabas although it is
absolutely good enough.
And the main
thing - the phase timing - is achieved only when the front
plane of the RAAL is 5 mm in front of the front plane of the Altec.
And since the
Altec is rear mounted by definition (the ribs) the
RAAL must be recessed accordingly. On the same plane they measure wrong
impulse response.
THE MIDRANGE
Altec Lansing
Biflex 420A - 15 inch, single coil - dulal QTS
(response limits: 28 Hz - 18k)
Paper membrane,
cloth surround, alnico magnet.
It has same
basket as the
bass drivers with 15 inch cast frame and Alnico V magnet, but the paper
cone is divided into two, connected by specially selected suspension.
Or rather two outer suspensions of sticky cloth.
It is like a 20
cm midrange glued to the circular remains of a 15" bass
driver. At frequencies around 100 Hz and below the mechanical
coupling allows the
surrounding bass part to start moving. Above that - the surround is too
heavy and behaves like a frame.
February 29 2008
Application of
the biflex is a real challenge. It does not behave like
a good boy, I mean like a poly seas driver so to speak.
Out of the box
they sound quite spectacular, especially that they go up
to
18k without sweat - that is without any filter. It is a really nice
wide-range speaker. But the sound is kinda harsh and rough.
After 4 evenings
with the driver I decided that I can't tolerate the
metal "dustcap" dome inside. This is really like a dome tweeter, not
just the dustcap.
It is supposed
to extend the speaker's response from 12 K to 18 K
and it does the trick very well on paper, but listening shows a
metallic
ringing which I hate.
So I decided
that is either me or the alu dome. I took the utility
knife and I cut the sucker out.
It was NOT EASY
THING from mental standpoint - I was sweating like a
pig.
Anyway - the
driver is now MUCH cleaner sounding - like a proper
vintage paper
midrange for 500 dollars should be. I recommend everybody to do the
same mod without slightest
hesitation.
Second thing -
despite amputation of the center dome - I traced on my
PC the very sharp peak at 10-12 K. The driver rolls nicely at 8 K then
there is plateau of silence, and a huge peak again. Something resonates
in the cone. I added a 10 uF paralell cap and it just removes that peak
whilst keeping the
signal intact. Perfetto !!!
So the final
schematics of a great sounding, totally resistorless
crossover for the midrange is:
- 100uF MKP
series cap, followed by 1,2 (+/- 0,2) mH series coil of low
DCR below 1 Ohm and followed by parallel cap of 10 uF, volts
unimportant, foil type.
I am VERY
confident in this XO, please do not deviate.
THE BASS
Altec Lansing
408B - 15 inch, single coil (response limits: 24 Hz
- 2k)
Paper membrane,
cloth surround, alnico magnet.
THE XO:
Tweeter:
first- C=4uF series, L=0,5 mH paralell,
Phase positive.
Mid: C=100uF
series (foil) then L=1,2 mH series, then C=10uF paralell.
Phase POSITIVE
Bass: L=4,7 mH
iron core R<0,5 Ohm, and paralell C=80 uF. Phase negative. Your
phasing may vary because my bass units are 1 m behind
the mids and tweeters. If they are on same plane - the mileage may vary.
No resistors are
used anywhere.
My amp which is
a 2 WPC OTL is perfectly happy driving these speakers
to levels at which the furniture starts moving around the room.
This is the test
drive baffle. Size is 45 x 90 but I want it 15 cm
higher and 5 cm wider. I also want the tweeter to be closer to the
mid. The point between the Altec and the RAAL should be on the
siting position- ear level (which for my chair, my height and my ears
is 1 m). Now it's the RAAL on ear
level and it sounds wrong. I HATE low sounding systems. I mean music on
knee height.
This photo is
crooked, but the
speaker is STRAIGHT VERTICAL. No tilt backwards.
At the time of
writing this system already meets my expectation - it is
my best to date and at the same time very very simple. Although not
cheap anymore - you are looking at:
900 Euro for the
RAAL
500 USD for the
Biflex plus 250$ for shipping from USA
same about the
bass.
To be continued
.....
also check
the P23 with similar drivers..
TWO
YEARS LATER
Well, two years
with these speakers and I still could not forget the SABA greencones. I
remembered - back in the saba days - I was having real eargasms and
goosebumbs and you name it. With the Altecs - I had to fake them.
So in the
end I decided to add the missing magic by going four-way and
adding a midrange driver. I felt that the Altecs are too heavy footed
to sing the blues.
But at the same
time I felt ashamed of being so conservative and using SABA again so I
picked another lovely driver - the ISOPHON OVAL.
it was known to
me from PROJECT
P18
I also briefly
experimented with the very interesting driver from Great Plains Audio
with a horn.
As sexy as the
hugely monstrous GPA drivers were, I was not liking their sound. I
tried many variants of my XO but every time the GPA kept the sound
strongly attached to them.
I
admit -the
GPA are not for me, I can't apply them properly with RAALs. I feel they
need special full horn system a'la AVANTGARDE TRIO to sing well.
Switching to the Isophon Ovals was a big improvement - music exploded
with 3-D-everywhere. And Isophon is 15 times cheaper.
It was time to build a new baffle so I designed everything from scratch.
Without my
Kingston Kitchen woodworking facility, I am very limited witrh
what I can do with the router.
Anybody who
tried routing MDF in the living room, will understand me. My wife -
doesn't.
I made the
smallest baffle which I think gives good results - I mean the baffle to
be good must be bloody large so anything acceptable in the living room
is already a compromise.
My baffle is 55
cm wide, 150 cm high, and 52 mm thick.
It is a sandwich
of a 12 mm plywood, 20 mm MDF (back side) and front decor of 20 mm
parquet floor panel.
The tweeter and
the oval are squeezed together, pretending to be a point source.
They fit very nicely.
I sprayed the
plywood black to make it ready for final assembly of the front
decor.
I chose exotic
wood parquet panels because they seemed fairly easy to apply. I was
wrong. They are a nightmare to work with.
The baffle has
simple foot made of scrap MDF. Just enough to hold them straight.
Sawdust and
persian rugs don't go together in perfect harmony like ebony and ivory.
NEW BASS SECTION
As you know
already, for me nothing beats the bass built-in the book shelves.
Simply nothing.
My long term
reference were Altec Lansing Alnico 15 inch drivers.
One day they
were beaten by the ultra rare and ultra expenceive Tesla ARO from
Czechoslovakia. Similar to Altecs, but with lower Fs, bigger magnet,
smoother cone and more pleasant bass sound.
Since it is
easier to find cash on the street than it is to find a decent pair of
Tesla 8 Ohm bass, I bought the 32 Ohm variant and I added a
transformer. To me it works just great.
The bass from
these drivers became so good, loud and deep, that the neighbours
downstairs threatened me with murder.
I decided to
suspend my system on a floating false floor.
I put 4 layers
of cork matts and I built a wooden floor on top of it. It was really
floating, not being attached, not even touching the walls. This helped
the neighbour problem and my own sound is stilll very good.
Tesla (left)
against the Altec (right as you might have guessed already)
I have later on
finished the floor's edge with a quarterround and I love the result.
FINAL
XO:
Tweeter: 2,2 uF
series, 0,5 mH parallel, 2nd order electrical at around 6-7K
Isophon: 100 uF
series, 1 mH series first order on both ends
Altec 420
Biflex: 2 mH series, 20 uF parallel second order lowpass at around 1-2
KHz . No Hipass.
Tesla ARO bass:
4,7mH series, 100 uF parallel, and 1:2 transformer to match 32
Ohms. Lopass at around 250 Hz. (amplifier load is R divided
by ratio squared which is 32 / 2*2 = 8 Ohms.)
Only tesla is
reversed polarity.
LISTENING
This system
became really good by now.
Bass has
improved by addition of suspended floor, and ARO from Tesla play better
than my Altecs. All in all - I am even more happy with this bass
solution AND I can play louder thanks to the floor thing. So I can
enjoy life more, while it lasts.
The midrange is
no compromise really. It is not as thin as from Saba alone, and not as
thick as from Biflex alone. The Isophon is my best midrange I ever had.
I love that little sucker. I am surprised how much bass it can produce
on that baffle. It is really very energetic and very smooth at the same
time. It's very stiff and solid basket is a class better than Sabas -
which tends to ring like a bell.
The RAAL tweeter
is great one, I have it for 3 years now and I wouldnt exchange it for
anything else.
Here it is - my
DELUSION project P24 at the end of the road.
Complicated it
may be because it is a fourway. The drivers are hard to get. So I don't
suggest that anybody should copy these but maybe you can get some
courage and inspiration to try your own search.
I am sticking
with these.
Compared to
everything that I had before, these speakers are most civillised,
neutral, natural, powerful, uncolored and true. I cant detect any
shortcomings.
The singers
sound like living humans. Drums sound like drums. Cymballs sound like
cymballs. Soundstage is wide, deep and tall. Everything I could ask
for. Roger Waters barks behind my head. Leslie Feist sings with
her head in the bucket. Ginger Baker drums like a mad
shaman. Wholle Lotta Love makes my chest hair grow.
THESE ARE MY
SPEAKERS with which I am gonna grow old. I will stop at that point and
there will be no more research in speaker department, at least for a
while.
Lukasz in the
state of bliss....
Parts for this project